Error handling in Python-MySQL

I am running a little webservice based on python flask, where I want to execute a small MySQL Query. When I get a valid input for my SQL query, everything is working as expected and I get the right value back. However, if the value is not stored in the database I receive a

Basically I just want to return a value, when everything is working properly and I want to return nothing if it isn't preferably with an error message on my server. How can I use error handling in a proper way?

Now do you really have to catch a TypeError here ? If you read at the traceback, you'll notice that your error comes from calling __getitem__() on None (nb : __getitem__() is implementation for the subscript operator []), which means that if you have no matching rows cursor.fetchone() returns None, so you can just test the return of currsor.fetchone():

Now do you really need to catch MySQL errors here ? Your query is supposed to be well tested and it's only a read operation so it should not crash - so if you have something going wrong here then you obviously have a bigger problem, and you don't want to hide it under the carpet. IOW: either log the exceptions (using the standard logging package and logger.exception()) and re-raise them or more simply let them propagate (and eventually have an higher level componant take care of logging unhandled exceptions):